1. Field of the Invention
The present invention generally relates to engines used with saddle-type vehicles.
2. Description of the Related Art
Saddle-type vehicles can have a number of different configurations, such as motorcycles, scooters, four-wheeled vehicles and the like. The vehicles generally include a rear arm which supports one or more rear wheels and a rear-arm bracket that supports the rear arm relative to a vehicle body. The rear-arm bracket usually has a pivot shaft about which the rear arm pivots. In other words, the rear arm is supported such that it can pivot about the pivot shaft.
In some configurations, the saddle-type vehicles employ V-belt continuously variable transmissions. These transmissions include a primary sheave (i.e., a driving pulley) that rotates with the rotation of an engine crankshaft, a secondary sheave (i.e., a driven pulley), and a V-belt that wraps around the primary sheave and the secondary sheave. The primary sheave, the secondary sheave, and the V-belt are generally accommodated in a belt chamber of a transmission case.
In many of these configurations, a starting kick shaft is used to start the engine. In addition, a clutch and a speed-reduction mechanism often are provided between a shaft that is coupled to the secondary sheave and a transmission drive shaft that outputs rotation from the transmission. For example, known engines include an engine in which a secondary sheave shaft and a drive shaft are connected via a centrifugal clutch and an idle shaft of a speed-reduction mechanism. The centrifugal clutch can be positioned in a crankcase of the engine. A chain or the like can be used to transfer the rotation of the drive shaft to the rear wheel. For instance, the chain can be wrapped around a sprocket provided on the drive shaft and a sprocket provided on a shaft associated with a rear wheel.
In JP-A-5-213262 (hereinafter, referred to as Patent Document 1), the starting kick shaft is disposed in a position opposite to the V-belt in the vehicle body so as not to interfere with the V-belt. More specifically, the V-belt automatic transmission is disposed on the right side of the illustrated vehicle body while the starting kick shaft is disposed on the left side of the vehicle. JP-A-6-48363 (hereinafter, referred to as Patent Document 2) discloses an engine in which the starting kick shaft and the V-belt automatic transmission are disposed on the same side of the vehicle body. In this engine, sufficient space is provided between the primary sheave and the secondary sheave and the starting kick shaft is disposed between the primary sheave and the secondary sheave. The starting kick shaft is disposed inside the outline of the V-belt as viewed from the side so as not to interfere with the V-belt.